A new environmental foundation backed by Hollywood actor Leonardo DiCaprio is pledging $US5 million ($A7.4 million) in aid to the Amazon, which has been swept by wildfires. Earth Alliance was created last month by DiCaprio and philanthropists Laurene Powell Jobs and Brian Sheth. It launched the Amazon Forest Fund in an announcement on its website on Sunday. The alliance is also seeking donations to help repair the Brazilian rainforest, often referred to as the "lungs of the planet". A record number of wildfires were reported across Brazil this year by federal experts, up 84 per cent over the same period in 2018. Australian Associated Press